(1) Field of the Invention
The present invention relates to high energy cathodic battery plates having a high discharge rate and more particularly to a process for producing stable nickel oxide cathodes having a valence approaching +4.0 and hence a high coulombic capacity for use in high energy density batteries.
(2) Description of the Prior Art
It is well known that a serious deficiency of nickel oxide cathodes is their instability as regards loss of capacity. Furthermore, the valence of nickel in the charged state is about +3 resulting in less than optimum coulombic capacity. Present nickel oxide cathodes are generally prepared by electrochemical oxidation. Some cathodes have also been fabricated from nickel oxide powders prepared by wet methods of oxidation, for example, persulfate oxidation. These nickel oxide cathodes have not however been suitable for high energy density applications due to the inherent instability, low capacity and lower power output of +3 valence nickel oxide. Stable nickel oxide powders having a valence approaching +4.0 have been prepared by ozonation. However, forming such powders into a cathode plate has not been successful in meeting the requirements of a high energy density battery. Such processes, for instance using adhesives or sintering, do not result in cathodes in which the electrochemical properties of nickel oxide have been maximized and fully exploited.
What is needed is a nickel oxide cathode plate which is stable, has high power density, contains nickel oxide whose valence approaches +4.0 to provide an electrode whose coulombic capacity is nearly double that of an electrode containing only +3 valence nickel oxide and is thus suitable for use in high energy density batteries, possibly as a substitute for presently used high-cost silver oxide cathodes.